SC1185A

• Synchronous design, enables no heatsink solution
• 95% efficiency (switching section)
• 5 bit DAC for output programmability
• On chip power good function
• Designed for Intel Pentium® ll requirements
• 1.5V, 2.5V @ 1% for linear section
• 1.265V ± 1.5% Reference available

• Pentium® ll microprocessor supplies
• Flexible motherboards
• 1.3V to 3.5V microprocessor supplies
• Programmable triple power supplies

The SC1185 combines a synchronous voltage mode controller with two low-dropout linear regulators providing most of the circuitry necessary to implement three DC/DC converters for powering advanced microprocessors such as Pentium® II .

The SC1185 switching section features an integrated 5 bit D/A converter, pulse by pulse current limiting, integrated power good signaling, and logic compatible shutdown. The SC1185 switching section operates at a fixed frequency of 140kHz, providing an optimum compromise between size, efficiency and cost in the intended application areas. The integrated D/A converter provides programmability of output voltage from 2.0V to 3.5V in 100mV increments and 1.30V to 2.05V in 50mV increments with no external components.

The SC1185 linear sections are low dropout regulators supplying 1.5V for GTL bus and 2.5V for non-GTL I/O. The Reference voltage is made available for external linear regulators.